A quarter of retirees don't believe their lives are better now that they are retired, according to a poll by NPR, the Robert Wood Johnson Foundation and the Harvard School of Public Health.

The poll looked at retirement views and experiences for people over age 50 who have retired, those who plan to and those who do not plan to do so. What they found is that people who haven't retired yet may have an idealized view of what retirement will be like, the report said.

"Those of us over 50 and working are optimistic about our future health and health care, but that optimism is not necessarily shared by those who have already retired," said Risa Lavizzo-Mourey, president and CEO of the Robert Wood Johnson Foundation. "Many people who have already retired say their health is worse, and they worry about costs of medical treatment and long-term care. Insights from the poll can help policy makers and others think about how to meet the needs of aging Americans. There are changes we can make to our health care system, finances and communities that might help ensure that our retirement years will be as fulfilling as we hope."